The present invention relates to electric fence lines comprising several electrically conductive wire strands woven along with several plastic monofilament yarns. More particularly, an additional electrically conductive wire strand is woven in a diagonally alternating pattern in relation to the conductive wires and plastic yarns.
Electrically conductive fence wires connected to a high voltage energizing source are used to fence in animals or to exclude animals from certain areas. If an animal contacts the energized fence line, an electric shock is administered to the animal.
It has long been recognized that thick steel wire is bulky and expensive to produce. Further, steel wire is subject to corrosion. Using other materials besides steel of a sufficient gauge to be break-proof is cost prohibitive. For instance, stainless steel would be corrosion proof, but in a gauge the same as the thick steel wire would be much more expensive. Other corrosive resistant materials such as tinned copper, aluminum, or galvanized steel could also be used as an electrically conductive wire. However, these materials are typically more expensive than stainless steel. Further, using any of these materials in a sufficient thickness to ensure their strength may cause them to be very bulky and heavy in shipping and in installation.
Flat tapes woven of plastic monofilament yarn and woven with a warp including multiple conductive wire strands have been found advantageous for use as electric fence lines because thin conductive strands of stainless steel or other corrosion proof material can be used. Because the conductive strands are so thin in these type tapes, much less of the conductive material is used than in a standard electric fence wire. Thus, the woven tapes are generally less expensive. These tapes are also enjoyed because they are very lightweight and easy to ship and install. These lightweight tapes are easier to relocate to modify or move a fenced area. Additionally, the lightweight tapes may be run over long distances, hundreds of feet, with less tensile force on the fence line.
Woven plastic tapes with a warp consisting of several conductive strands have still further advantages over the traditional single strand wire fence. In particular, the plastic tapes may be colored brightly to make them more visible to animals and humans. The visibility of the tapes prevents accidental electric shock and prevents accidental contact by vehicles and the like. A further advantage of these tapes comprising several conductive strands is that a particular strand or strands may break, but some strands may remain intact. Therefore, the fence will remain partially electrified, but at a higher resistance, even with some discontinuity of the conductors.
But these tapes have been found to have certain disadvantages. A primary example is that the thin electrically conductive wires of the tape""s warp often break. When the thin conducting wires break, the electrified tape becomes less effective for administering an electric shock. A broken wire causes a discontinuity in the flow of the electric current in that particular conductive wire of the tape, increasing the overall electrical resistance of the tape. If several of the wires break, the resistance to the flow of the electric current is further increased and the downstream voltage and effectiveness of the electric fence tape decreases, accordingly.
Unfortunately, broken conductive wire strands in woven electric fence tape has been a persistent problem because the electrically conductive wires used in the tapes are so thin and fragile. Also, these tapes are frequently twisted and pulled during installation. The tapes are rolled and bundled for relocating or storing, and the flat plastic tapes are often installed by tacking them to fence posts. All of these factors and others contribute to conductive wires breaking.
It would be desirable to provide a flat woven tape construction for an electrically conductive fence line that mitigates these disadvantages.
U.S. Pat. No. 5,036,166 to Monopoli discloses a woven electric fence tape wherein a conductive wire having lower electrical resistance is woven in the warp of the tape and a conductive wire of higher strength and higher electrical resistance is interwoven in the tape and at intervals is traversed laterally of the tape for it to extend across the width of the tape. Monopoli claims that the weaving technique used to weave the Monopoli tape is well known in the art. Besides the specification of known weaving techniques in the 5,036,166 patent, Monopoli does not teach a means for weaving a low resistance conductive wire in bridging contact with electrically conductive warp strands.
The present invention provides an electric fence line comprising a flat tape or webbing preferably constructed of polyethylene or similarly suitable monofilament yarns. The warp of said tape further includes several electrically conductive wire strands woven parallel along with the monofilament yarns. An additional electrically conductive wire strand, referred to herein as a bonding strand, is woven in a diagonally alternating pattern in relation to the warp yarns and conductive wire strands by using a needle situated above said yarns and conductive strands to weave the bonding wire.
Ordinarily, in weaving a reed maintains proper separation of the warp yarns and also assists to pack the weft yarn into position after insertion. In the present invention, the ordinary reed has been replaced by a device, referred to herein as a comb. The comb has an open top end having several teeth. The gap between each of the teeth of the comb is utilized such that the needle can lift the bonding wire over the warp yarns and the comb for repositioning.
A synchronized cam moves the needle into position above the webbing for insertion of the bonding wire into a specified point in the webbing during the weaving process such that the bonding wire crosses over the conductive wire strands of the tape""s warp while the warp strands are on top of the tape. Thereby, the bonding wire contacts each conductive wire as it crosses the tape diagonally.